Police yesterday announced the arrests of Karl-Heinz Hoffmann, the head of an outlawed neo-Nazi group, and five of his followers for the bomb attack that killed 12 persons at the Oktoberfest in Munich Friday night.

A seventh member of the group was believed by police to have been among the dead following the blast.

Authorities said that four of the "Military Sports Group Hoffman" were arrested trying to cross into Austria Saturday. The Hoffman group, with a membership of about 400, was banned in January for its extreme rightist activity.

Police found papers pertaining to the group near the body of Gundolf Koehler, 21, the student suspected of planting the bomb in a trash can near the crowded exit from the Oktoberfest grounds.

The powerful explosive went off before Koehler could leave the scene, police theorized.The blast tore through a crowd leaving the Munich beer festival, which is billed as "the biggest folk festival in the world."

Authorities also revised the list of injured from the blast from 144 to 213. Among the injured, they said, were seven Americans. They were identified as Cynthia Fox, of Loomis, Calif.; John D. Fox, of Mountain Home, Idaho; Denise Fowler, of Sparta, N.Y.; Jim Evans of Montague, Mich.; Mark Kaufenburg, of St. Paul, Minn.; Eva Lidwinski and Marie Shoole, whose hometowns were not given.